Xerographic powder image transfer apparatus



Aug. 8, 1961 UB IWERKS 2,995,108

XEROGRAPHIC POWDER IMAGE TRANSFER APPARATUS Filed June 2, 1958 3Sheets-Sheet 1 INVENTOR. Ub lwerks 1951 U8 IWERKS XEROGRAPHIC POWDERIMAGE TRANSFER APPARATUS Filed June 2, 1958 3 Sheets-Sheet 2 INVENTOR.

Ub lwerks Q NY Aug. 8, 1961 us IWERKS 2,995,108

XEROGRAPHIC POWDER IMAGE TRANSFER APPARATUS Filed June 2, less 3Sheets-Sheet s INVENTOR. U b lwer ks Unite This invention relates to thefield of xerography and, particularly, to an improved apparatus fortransferring a xerographic powder image from a xerographic plate to asupport surface.

More specifically, the invention relates to an improved type ofapparatus that is particularly adapted for the production of cartoonmovies wherein it is required to effect a series of sequential transfersof xerographic powder images from a xerographic plate to successivesupport surfaces, and whereby, in many instances, the Xerographic plateand support surface must be relatively displaced on each succeedingtransfer to effect the simulation of motion in the final completed film.

In the process of Xerography, for example, as disclosed in CarlsonPatent 2,297,691, issued October 6, 1942, a xerographic plate comprisinga layer of photoconductive insulating material on a conductive backingis given a uniform electric charge over its surface and is then exposedto the subject matter to be reproduced, usually by conventionalprojection techniques. This exposure discharges the plate areas inaccordance with the light intensity that reaches them, and therebycreates an electrostatic latent image on or in the photoconductivelayer. Development of the latent image is effected with anelectrostatically charged, finely divided material such as anelectroscopic powder that is brought into surface contact with thephotoconductive layer and is held thereon electrostatically in a patterncorresponding to the electrostatic latent image. Thereafter, thedeveloped xerographic powder image is usually transferred to a supportsurface to which it may be fixed by any suitable means.

Various means are proposed in the Carlson patent for transferring thexerographic powder image onto the support surface dependent upon thetype of powder employed and the substance material of the supportsurface. For example, it is suggested an adhesive surfaced paper may beused as the support surface and that the adhesive side thereof bepressed firmly in contact with the powdered image to effect transfer.Wax or paraffin are typically recommended forms of adhesives. Where thepowder or dye is of a soluble composition, a support surface wetted witha suitable solvent may be applied firmly in contact with the powderedimage, thereby effecting transfer to the support surface.

Advances in the xerographic art showed a need for increasingly accurateand more positive transfer means. In todays state of the art, transferof a xerographic powder image from a xerographic plate to a supportsurface is usually achieved through the use of a corona generatingapparatus which is an adaptation of the Image Transfer Device disclosedby Sabel and Mayo Patent 2,684,901, issued July 27, 1954. When placed intransfer relation to a support surface superposed on a xerographicpowder image, the corona generating apparatus, by electrostaticallycharging the support surface, causes the powder im age to transfer andadhere to the support surface. The transferred image can then be fusedon the support sur face by conventional xerographic techniques.

In the above-cited Carlson patent it is noted that a variety of types offinely divided electroscopic powders may be employed for developingelectrostatic latent images. However, as the art of xerography hasprogressed, it has been found preferable to develop line copy imageswith a powder formed of any of a variety of pigmented 2,995,108 PatentedAug. 8, 1961 resins that have been specifically developed for thepurpose. A number of such developing materials are commerciallyavailable and are specifically compounded for producing dense images ofhigh resolution and to have characteristics to permit convenient storageand handling.

Such developing materials are specifically designed to permit them to beelectrostatically transferred and then fixed to support surfaces eitherby conventional heat or vapor fixing techniques, in accordance with theparticular application in which they are employed. Where the sup portsurface is composed of a material or substance such that it isimpractical or unfeasible to permit fixing the powdered image byconventional applications of these methods, as, for example, in thefixing of a powdered image onto a cellulose acetate support surface orcel, of the type employed in the preparation of cartoon movies, a methodand apparatus disclosed in copending application S.N. 674,777, filedJuly 29, 1957, in the name of Ub Iwerks, entitled Xerographic FusingApparatus, may be preferred.

In general, to prepare a cartoon movie, each frame of the finished filmis exposed to a group of four or more cellulose acetate transparencies,upon which are drawn and painted the various figures in the cartoon.Usually, each transparency or eel is employed to depict a singlecharacter and a progression of cels with minute variances are necessaryto portray the successive movements required to simulate motion in thefinished film. Sometimes a drawing may appear on only one of the celsthat are being photographed, but in -all cases in a given film sequencea uniform number of cels are stacked together before exposure in orderto maintain consistency of light transmission and reflection. Backgroundscenes are usually painted on one of several types of artist paintingboards and may be painted in water color, tempera color, or an oilcolor, and are positioned behind the cels being photographed.

An illustration of the above application would be a scene portraying anautomobile in motion. The automobile must appear continually to advancein its direction of travel relative to its natural surroundings. Thiseffect is attained by slightly displacing the automobile on eachsucceeding cel, so that when photographed in relation to fixedbackground scenery, there will result a filmed scene portraying theautomobile in continuous movement. The amount of eel displacementrequired is a function of the rate of motion to be simulated and isdetermined from calculated or empirically prescribed relationships.

Prior to the application of xerographic techniques to the production ofcartoon movies, the preparation of the individual cels requiredthat anartist draw a pencil sketch of the desired figure on heavy white bondpaper in exact registration of the scene to be portrayed. The paperemployed was specially prepared with a series of holes punched along oneedge which were used for alignment and registration purposes. When thedrawing was completed, it was passed on to a tracer who placed acellulose acetate eel having similar registration holes over theoriginal drawing and copied all the pencil lines of the original sketchwith pen and ink. The inked drawing was then passed to another artistwho colored the ink outlines on the reverse side of the cel, accordingto a predetermined coloring sketch. After the painting was completed,the several cels required to form a particular scene were mounted on aboard using the holes to achieve proper registration and werephotographed to form a single frame of the movie.

Since normal motion picture projection speeds are twenty-four frames persecond and a minimum of four cels are required to be prepared for eachframe, it is apparent that a full minute of projection requires thepreparation of thousand-s of cels and that the preparation of a two-reelshort requires the expenditure of a tremendous amount of effort. Inaddition, since highly skilled artists are required for this work, it isapparent that the cost of making cartoon movies is quite high. In orderto decrease these costs, it was found that xerographic techniques couldbe employed to eliminate a substantial portion of the skilled manualcraftsmanship that was previously employed. Specifically, it was foundthat xerocopies of the original artist sketches could be transferreddirectly to cels and fused thereon, thereby eliminating completely allof the manual tracing previously required. In addition, it was foundthat certain of the artists shading effects, that were normally lost inthe manual tracing, could be retained by the careful application ofxerographic techniques to improve the quality of the finished cartoon.

In practice, in the application of xerographic techniques to theproduction of cartoon movies, a xerographic plate comprising aphotoconductive layer formed on a conductive backing is provided with auniform electrostatic charge on the photoconductive layer which then isexposed to a light image of the sketch required to be reproduced,usually by conventional projection techniques. This exposure dischargesthe xerographic plate in the lighted areas thereof retaining a latentelectrostatic image of the sketch on the photoconductive layer. Thislatent image is then developed by cascading a xerographic developingmaterial over the surface of the plate whereby the pigmented resincomponent of the developing material adheres to the latent image to forma xerographic powder image of the sketch on the plate. Thereafter, thexerographic powder image is transferred to the surface of a celluloseacetate cel, by conventional electrostatic transfer techniques, and isthen fixed on the cels surface.

The foregoing technique provides an accurate and economical way offorming cels for use in the production of cartoon movies and ispresently in commercial use for this purpose. In addition, it has beenfound that at least portions of the cartoon movie can be simplified inproduction by a further application of xerographic techniques. Forexample, in the illustration noted above, namely, the automobile inmotion against a background scene, it may be assumed that in at least aportion of a given film sequence, the automobile will retain a givenconfiguration through a succession of at least several frames. Toachieve the illusion of motion, the automobile may be advanced onsuccessive frames relative to a fixed background, or it may remain fixedrelative to the projection screen while the background is caused tomove. In either case, it is apparent that each scene of a series ofsuccessive frames can comprise repetitions of the same backgroundconfiguration and the same automobile out line merely by displacing onerelative to the other.

Prior to the application of xerographic techniques to cartoon moviepreparation, the above displacement procedure for successive cels wasachieved by visual perception. As each successive cel was manuallytraced from the artists sketch as hereinbefore described, the tracerwould visually and painstakingly reposition the succeeding cel beforetracing. It is apparent that these means require employment ofskillfully trained personnel and at best provided a limited accuracy fordisplacement. In the alternative, duplicate cels were traced in exactregistration of artists sketches and successive cels were visuallydisplaced when mounted for photographing the finished scene.

The principal object of this invention is to improve transfer of axerographic powder image from a xerographic plate to a support surface.A further object of the invention is to effect precise registrationbetween a xerographic powder image and a support surface. A furtherobject of the invention is to effect precise relative positioningbetween a xerographic plate and a support surface. A further object ofthe invention is to provide a corona generating apparatus for effectingtransfer of a xerographic powder image from a xerographic plate to asupport surface in combination with devices for elfecting preciserelative positioning of a xerographic plate and a support surface. Afurther object of the invention is to provide means for positioning acorona generating apparatus from image transferring relation to aparallel ineffective and stable position.

These and other objects of the invention are attained with the apparatusof the invention comprising a work table with lateral and longitudinalslides on the work table surface, an independent means for relativelypositioning each of the slides, a means for aligning and securing aXerographic plate on one prepositioned slide, a means for aligning andsecuring a support surface on the other prepositioned slide, a coronagenerating apparatus supported on the work table for effecting transferof a xerographic powder image from a xerographic plate to a supportsurface and a means for positioning the corona generating apparatus inpowder image transferring relation to a xerographic plate and supportsurface secured on the slides.

A preferred form of the invention is embodied in the accompanyingdrawings, in which:

FIG. I is an isometric view of the apparatus of the invention, showing axerographic plate and a cel in position for effecting image transfer;

FIG. 2 is an isometric view of the apparatus of FIG. 1 in imagetransferring position;

516. 3 is an isometric cut-away view of the work ta le;

FIG. 4 is a longitudinal section view through the work table top;

FIG. 5 is a lateral section view through the work table top; and

FIG. 6 is an isometric cut-away View of the corona generating apparatusand the parallel linkage supporting mechanism therefor.

In the form of apparatus shown on the drawings the invention includes arectangular work table 1, a corona generating apparatus 2 which intransfer relation serves to provide a uniform electrostatic charge to asupport surface thereby effecting transfer of the powdered image from axerographic plate to the support surface; a parallel linkage mechanism 3for raising and lowering the corona generating apparatus 2 from the worktable surface, a longitudinal positioning mechanism 8 and lateralpositioning mechanism 9 for prepositioning a xerographic plate andsupport surface, respectively.

For positioning xerographic plates and cels support surfaces thehorizontal top surface 10 of work table 1 is provided with alongitudinal groove 11 (FIG. 5) for insertion therein of longitudinalslide 12 and a lateral groove 13 (FIG. 4) for insertion therein oflateral slide 14. In approximate center of table surface 10, is adepressed rectangular area 15 in which is inserted lateral slide 14extending laterally through the center of 15 and filler plate 16 whichin cooperation with lateral slide 14 forms a substantially flathorizontal surface to accommodate xerographic plate 6 (shown in FIG. 1).When set on top of lateral slide 14 and filler plate 16, the top surfaceof xerographic plate 6 forms a substantially continuous horizontalsurface with work table top surface 10 for superposing thereon oftransfer support surface 7.

Secured to the top of lateral slide 14 and perpendicular to its mainaxis is cross member 21. On the top surface of cross member 21 andupwardly protruding therefrom are rectangular shaped pins 17 andcylindrically shaped pin 18 which serve to secure a xerographic plate 6to the work table surface and effect alignment thereof withcorresponding similarly shaped holes in said xerographic plate 6.Similarly, on the top surface of longitudinal slide 12 are upwardlyprotruding cylindrical pins 19 and substantially oblong shaped pins 20which serve to secure a support surface 7 to the work table surface andeffect alignment thereof with corresponding similarly shaped holes insaid transfer support surface 7.

Assembled below the top surface of table top are longitudinalpositioning mechanism 8 and lateral positioning mechanism 9 which serveto position longitudinal slide 12 and lateral slide i4, respectively.Turning of handwheel 23 secured on laterally extended shaft 24 effects alongitudinal movement of slide 12 by transmitting the angular movementof 23 through shaft 24 to pinion 25 also secured on shaft 24 thence togear secured on rotatable shaft 31 and thence to rack 26 which isintegrally attached to the underside of slide 12 and is in continuousengagement with gear 30. Coincident with the turning of handwheel 23,counting mechanism 27 secured on shaft 24 and engaged with countingindicator 28, transmits the measured position of slide 12 to a visuallylegible indicator dial at window 29. Similarly, turning of handwheel 32secured on laterally extended shaft 33, elfects a lateral movement ofslide 14 by transmitting the angular movement of handwheel 32 throughshaft 33 to bevel gear 34 secured thereon, thence to bevel gear 35secured on longitudinally extended shaft 36 to pinion 37 also secured onshaft 36, thence to gears 42 and 44 each secured on rotatable shaft 43,thence to gear 45 engaged with rack 38 which is integrally attached tothe underside of slide 14. Coincident with the turning of handwheel 32,counting mechanism 39 secured on shaft 33 and engaged with countingindicator 40 transmits the measured position of slide 14 to a visuallylegible dial at window 41. It is apparent from the foregoing that, bymanipulation of either or both handwheels 23 and/or 32, accuratepositioning of either slide 12 or 14 may be effected independently andthereby elfect a prepositioned relationship between a Xerographic plateand a support surface subsequently secured to their respective slides.

Corona geenrating apparatus 2, in transfer relation, functions togenerate a uniform electrostatic charge over the transfer supportsurface 7 thereby effecting transfer of the powdered image from thexerographic plate 6 onto the transfer support surface 7 by electrostaticattraction. Referring to FIG. 6, the corona generating apparatus iscomprised of supporting frame 46 which serves to position allcomponents; conductive rails 47 and 48 each secured to frame 46 andinsulated therefrom by insulators 49; and a discharge electrode assemblyor scorotron 50 slidably mounted in frame 46 to pass over transfersupport surface 7 (FIG. 2) when generating apparatus 2 is intransfern'ng relation. The scorotron 50 is comprised of a supportchannel 51, generally of conductive material, carrying at each endinsulating blocks 52 between which are strung two sets of wires.Scorotron 50 is supported in frame 46 by hangers 53 and 54 which slideon rails 47 and 48, respectively. Each hanger is connected to a separateset of wires whereby the potential of each set of wires may becontrolled by applying an appropriate potential to the correspondingrail from power source 58. High voltage power supply 58 is connected toside rails 47 and 48 through wires 62 and 63, respectively, whichvoltage is thereby transmitted to scorotron 56. Corona wires (not shown)are usually charged with a potential in the range of 6000-8000 voltswhereas screen wires 61 are usually charged with a potential in therange of 600-800 volts. Frame 46 also supports rotatable reversing leadscrew 55 which is adapted to move the scorotron 50 back and forth bymeans of the lead screw block 56 which engages the groove in the leadscrew 55 and is attached to support channel 51. Electric motor 57 ispivot mounted to frame 46 whereby wheel 64, secured to the motor shaftof motor 57, is continually engaged by surface friction to lead screwwheel secured to lead screw 55 thereby effecting rotation of lead screw55. Microswitch 59 is usually provided to stop motor 57 and scorotron 50after scorotron 50 traverses one cycle forth and back to its startingposition. Alternatively, other mechanical arrangements may be used.

In operation, corona generating apparatus 2 is placed in transferringrelation over transfer support surface 7 as shown in FIG. 2. Powersupply 58 and motor 57 are simultaneously energized through switching ofmicroswitch 59 causing scorotron 50 to traverse over support surface 7and deposit charge thereon. Said charge on support surface 7 attractsthe powdered image from the xerographic plate 6 onto the support surface7. Switch 60 provides a safety disconnect of the power supply to thecorona generating apparatus 2.

Parallel linkage mechanism 3 is comprised of two sets of supportbrackets 67, rocker arm brackets 68, and pivot arm bracket 69 assembledin mirror-image relation and joined by counterweight 70. Supportbrackets 67 attach to work table 1, by means of bolting, welding orother suitable means. Extending perpendicular and upward from bracket67, and as an integral and fixed part thereof, is cantilevered arm 71,which is journaled at 72. Main shaft 74 extends longitudinally behindbrackets 67, through journals 72 and is secured at both ends by rockerarm brackets 68. counterweight is secured at both ends by boltingthrough at the lower end of rocker arm bracket 68 with bolts into eachtapped end of counterweight 70. Pivot arm bracket 69 is pivot mounted toarm 71 by trunnion 76. Rocker arm brackets 68 connect to support frame46 of corona generating apparatus 2 by bolt 78 through sleeve bearing(not shown) in bracket 68 into tapped boss 79 of frame 46. Similarly,pivot arm bracket 69 connects to support frame 46 by bolt 80 insertedthrough the forward end of bracket 69, through washer 81 into tappedboss 82 of frame 46.

By the arrangement above described, the corona generating apparatus 2can be lifted from operative transfer relation shown in FIG. 2 to itsextreme inoperative position shown in FIG. 1, with the apparatuscontinually maintained in a horizontal plane. By maintaining coronagenerating apparatus 2 in a parallel horizontal plane the scorotron 50is mintained in concealed relation to the human operator therebyaffording safety protection to the operator from inadvertent contactwhile said scorotron is charged with a high potential. Similarly, theprecision made scorotron is protected from accidental damage from anypassing object. Counterweigh-t 70 serves to effect stability of thecorona generating apparatus 2 when in its inoperative position therebypreventing said apparatus from falling downward during its period ofinoperativeness.

Raising corona generating apparatus 2 by handle 83 transmits themovement through rocker arm bracket 68 and about shaft 74 in journal 72.Simultaneously, movement is transmitted through pivot arm bracket 69about trunnion 76. The relative connection points, generalconfiguration, and turning points of brackets 68 and 69 maintaingenerating apparatus 2, in a parallel horizontal plane.

By the arrangement thus described there is provided a xerographictransfer apparatus that enables rapid and precise positioning between axerographic plate bearing a xerographic powdered image and a transfersupport surface in combination with means to elfect transfer of thexerographic powdered image to the support surface. There is providedthereby, expedient xerographic transfer means for the preparation ofcartoon movies.

Obviously, many changes could be made in the abovedescribed constructionand a number of apparently different embodiments of apparatus could bemade within the scope of the invention. Therefore, it is intended thatall matter contained in the above description shall be considered asillustrative, and that the invention be limited only as defined in theappended claims.

What is claimed is:

1. An apparatus for transferring a xerographic powder image from axerographic plate to a support surface superposed thereon, comprising awork table, lateral and longitudinal slides on the work table surface,independent means for relatively positioning each of the slides, a

7 means for aligning and securing a xerogr-aphic plate on oneprepositioned slide, a means for aligning and securing a support surfaceon the other prepositioned slide, whereby said aligning means serve toalign a plate and support surface one above the other, a coronagenerating apparatus supported on the work table for effecting transferof a xerographic powder image from a xerographic plate to a supportsurface, and means for positioning the corona generating apparatus inpowder image transferring relation to a xerographic plate and a supportsurface secured on the slides.

2. An apparatus for transferring a xerographic powder image from axerographic plate to a support surface superposed thereon comprising awork table, lateral and longitudinal slides on the work table surface; afirst grooved slot arranged laterally in the work table surface toaccept and guide a lateral slide; a second grooved slot arrangedlongitudinally in the work table surface to accept and guide alongitudinal slide; independent means for relatively positioning each ofthe slides in its respective groove, a means for aligning and securing axerographic plate to one prepositioned slide; and means for aligning andsecuring a support surface to the other prepositioned slide, wherebysaid aligning means serve to align a plate and support surface one abovethe other, a corona generating apparatus supported on the Work table foreffecting transfer of a xerographic powder image from a xerographicplate to a support surface, and means for positioning the coronagenerating apparatus in powder image transferring relation to axerographic plate and a support surface socured on the slides.

3. An apparatus for transferring a xerographic powder image from axerographic plate to a support surface superposed thereon comprising awork table, lateral and longitudinal slides on the work table surface; afirst grooved slot arranged laterally in the work table surface toaccept and guide a lateral slide; a second grooved slot arrangedlongitudinally in the work table surface to accept and guide alongitudinal slide; an independently operative gear drive mechanismconnected to the one slide; an independently operative gear drivemechanism connected to the other slide; a means to independently actuateeach gear drive mechanism to effect relative positioning of thelongitudinal and lateral slides; pins on one prepositioned slide foraligning and securing a xerographic plate thereto; pins on the otherprepositioned slide for aligning and securing a support surface thereto;whereby the pins on said slides serve to align a plate and supportsurface one above the other, a corona generating apparatus supported on.the work table for effecting transfer of a xerographic powder imagefrom a xerographic plate to a support surface, and means for positioningthe corona generating apparatus in powder image transferring relation toa xerographic plate and a support surface secured on the slides.

4. An apparatus for transferring a xerographic powder image from axerographic plate to a support surface superposed thereon comprising aWork table, lateral and longitudinal slides on the work table surfaces;a first grooved slot arranged laterally in the work table surface toaccept and guide a lateral slide; a second grooved slot arrangedlongitudinally in the work table surface to accept and guide alongitudinal slide; an independently operative gear drive mechanismconnected to the one slide; an independently operative gear drivemechanism connected to the other slide; a means to independently actuateeach gear drive mechanism to effect relative positioning of thelongitudinal and lateral slides; pins on one prepositioned slide foraligning and securing a xerographic plate thereto; pins on the otherprepositioned slide for aligning and securing a support surface thereto;whereby the pins on said slides serve to align a plate and supportsurface one above the other, a corona generating apparatus pivotallymounted on the work table for effecting transfer of a xerographic powderimage from a xerographic plate to a support surface; a parallel linkagemechanism connecting the corona generating apparatus to the work tablewhereby the generating apparatus may be moved to an efiective positionin which it is in powder image transferring relation to a xerographicplate and support surface secured on the table or to an ineffectiveposition in a parallel plane to the Work table surface; and acounter-balancing weight in the parallel linkage mechanism to maintainthe corona generating apparatus in either its effective or in itsineffective position.

5. Apparatus for transferring a xerographic powder image from axerographic plate to a support surface superposed thereon, saidapparatus including a work supporting surface, a corona generatingapparatus supported in operative relation to said work supportingsurface and adapted for effecting transfer of a xerographic powder imagefrom a xerographic plate to a support surface, a first slide memberoperatively arranged on said work supporting surface and having meansfor aligning a xerographic plate on said work supporting surface inoperative relation to the corona generating apparatus, and a secondslide member operatively arranged on said Work supporting surface andhaving means for aligning a support surface in superposed relation to axerographic plate aligned by first slide member, whereby said aligningmeans serve to align a Xerographic plate and support surface one abovethe other.

6. Apparatus for transferring a xerographic powder image from axerographic plate to a support surface superposed thereon, saidapparatus including a work supporting surface, a corona generatingapparatus supported in operative relation to said work supportingsurface and adapted for effecting transfer of a xerographic powder imagefrom a xerographic plate to a support surface, a first slide memberarranged to move laterally on said work supporting surface, a secondslide member arranged to move longitudinally on said work supportingsurface, means on one of said slide members to align a xerographic plateon said work supporting surface in operative relation to the coronagenera-ting apparatus, means on the other of said slide members to aligna support surface in superposed relation to a xerographic plate alignedon said work supporting surface, whereby said aligning means serve toalign a xerographic plate and a support surface one about the other, andvariably settable means connected to each slide member to effectmovement of the slide members relative to each other.

References Cited in the file of this patent UNITED STATES PATENTS1,829,562 Kohlwey Oct. 27, 1931 2,626,865 Mayo et al Jan. 27, 19532,647,464 Ebert Aug. 4, 1953 2,684,902 Mayo et a1 July 27, 19542,752,271 Walkup et al June 26, 1956 2,791,949 Simmons etal May 14, 1957

